ABSTRACT
Objective:To choose the best vector for the expression of CS3 fimbriae. Methods: The CS3 operon was cloned into different plasmid vectors such as pUC19 and pTrc99A. The expression of CS3 was monitored by whole-cell ELISA and SDS-PAGE analysis. The assembly of CS3 fimbriae was detected with electron microscopy. Results:The expression level of CS3 fimbriae using plasmid pUC19 as carrying vector was the highest, and the insertion orientation of CS3 gene into the plasmid has a little effect on its expression level. The expression of CS3 fimbriae was confirmed by SDS-PAGE analysis and electron microscopy.Conclusions:The promotor of CS3 itself played the key role in the expression of CS3 fimbriae and the copy number of plasmid was the main factor to affect the expression level.